This invention relates to the art of electroplating palladium and its alloys. Numerous plating baths have been proposed for this purpose. Typical baths are taught, for example, in U.S. Pat. Nos. 3,580,820; 3,933,602; and 3,972,787. The foregoing patents discuss systems containing, for example, palladium di- and tetramine halides, palladium-urea sulfite complexes, palladium dinitrite complexes, palladium tetramine nitrate or sulfate complexes, and palladium amine sulfite complexes.
It would be desirable to be able to improve the brightness of palladium or palladium alloy deposits. It would also be desirable to have available in the art a palladium electroplating bath which can be employed to obtain a bright deposit on iron, cobalt or nickel substrates which are normally passivated under alkaline conditions.